A

AFIS

Automated Friction-ridge Identification System, formerly defined as Automated Fingerprint Identification System, but modified because of the introduction of palm and plantar identification capabilities.

ANSI-NIST/ITL 1-2011

NIST Special Publication 500-290 Data Format for the Interchange of Fingerprint, Facial & Other Biometric Information. It is the base standard that defines mandatory field requirements, optional fields, and rules for configuring options. It is used as a basis for defining specifications for transactions between interconnected systems, e.g., FBI EBTS v9.3.

Arch

A fingerprint pattern in which the ridges enter on one side of the impression, and flow, or tend to flow, out the other with a rise or wave in the center.

B

Bifurcation

A type of minutia defined by the division of one friction ridge into two friction ridges.

C

Clarity

The fidelity with which anatomical details are represented in a friction ridge impression. Clarity corresponds to an examiner’s confidence that the presence, absence, and details of the anatomical friction ridge features in that area can be correctly discerned in that impression.

Core

In EFS, a core is the focus of the innermost recurving ridge in a fingerprint. Cores are found in loops, whorls, and some tented arches. In the past, other definitions have noted different locations for cores, including AFIS-specific definitions. The Science of Fingerprints defines core as the topmost point on the innermost upwardly curving friction ridgeline, which differs from the EFS definition; this definition was not used in EFS because the EFS location is more reliably determined in AFIS. Under EFS, core-like patterns in palmprint, lower joints, or plantar impressions should be marked in the same way as cores.

Core-Delta Ridge Counts

A count of intervening ridges between a core and a delta; only applies to loops and whorls. It is used to obtain greater granularity in fingerprint classification and is a feature used for comparison of a latent with the exemplar.

Crease

Flexion creases are found between movable parts of the hand (and foot). Those creases are embedded in the skin and mostly fit naturally in the ridge flow. The flexion creases are permanent and may show particular skin shapes such as crow feet. A line or linear depression; grooves at the joints of the phalanges, at the junction of the digits and across the palmar and plantar surfaces that accommodate flexion.

Other creases are skin folds; their presence increases as the skin ages. The friction ridges are lower for the path of the crease causing the ridges not to print and leaving a white line without information. They are also called white lines.

D

Delta

A delta is a meeting point of three (3) individual ridge flows. Deltas are found in fingerprint loop and whorl patterns and may occur in tented arches. They are common in the interdigital palmprint area.

Direction Uncertainty

A range that may be defined if a feature’s direction cannot be accurately determined.

Distal Segment

The segment of a finger or thumb farthest from the palm.

Distinctive feature

An unusually discriminating/unique feature such as scars that cannot be defined adequately using other features.

Dot

A dot is an isolated single ridge unit (ridge that contains a single pore). Generally, the width of a dot is similar to the width of neighboring ridges, and the length of a dot approximates its width.

E

EBTS

The FBI’s Electronic Biometric Transmission Specification (EBTS v9.3) (which supports NGI Increment 3, and supports certain elements of ANSI/NIST-ITL 1-2011) defines the specifications to which agencies must adhere when electronically communicating with the FBI’s NGI (formerly IAFIS). The specification provides descriptions of all requests and responses associated with electronic fingerprint identification services, including 10-print, latent, and fingerprint image services.

EFS Differences with NCIC Classification Methodology

EFS differs from the NCIC Classification methodology in its locations for cores: the EFS location of cores for loops is at the focus of the innermost recurving ridge, rather than on the ridge itself; EFS also defines core locations for whorls and some tented arches. The EFS core locations were developed based on input from AFIS vendors and SWGFAST, specifically because these locations are not as sensitive to the presence or absence of ridge appendages or crossing ridges, and are therefore more reliably detected by automated systems.

Exclusion

The determination by an examiner that there is sufficient quality and quantity of detail in disagreement to conclude that two areas of friction ridge impressions did not originate from the same source.

Exemplar

An impression or image of friction ridge skin purposely collected with the knowledge of the subject; a non-latent friction ridge image.

Extended Feature Sets (EFS)

A set of friction ridge features defined in the ANSI-NIST-ITL 1-2011 standard, and used in the FBI’s EBTS. The EFS fields are designed to be interoperable among AFIS systems, as well as to document latent friction ridge features for archiving or exchange between latent examiners.

F

Finger/Palm/Plantar position

The specific finger, thumb, or palm or plantar area that created an impression.

Fingerprint

An impression of the friction ridges of a finger or thumb. While this may be used to refer to impressions from any part of a finger or thumb, it is most frequently used to refer to impressions from distal segments.

Fingerprint Examination

Fingerprint or palmprint examination is the process of analysis, comparison, evaluation, and verification of friction ridge impressions.

Fingerprint Pattern

See Pattern Classification.

Friction Ridge

A raised portion of the epidermis on the palms of the hand or the soles of the feet, consisting of one or more connected ridge units of friction ridge skin. Synonymous to ridge.

Friction Ridge Skin

The skin found on the palms of the hands and soles of the feet.

Friction Ridge Unit

Single section of a friction ridge containing one pore.

H

Henry Classification

A system of fingerprint pattern classification named for Sir Edward Richard Henry (1850 - 1931).

I

Identification

See individualization.

Impression

Friction ridge detail deposited on a surface. Synonymous to print.

Incipient Ridge

An incipient is a thin ridge, substantially thinner than a normal ridge width. Incipient ridges generally do not contain pores. Incipient ridges frequently appear as a series of separate segments.

Inconclusive

The determination by an examiner that there is neither sufficient agreement to individualize, nor sufficient disagreement to exclude.

Individualization

The determination by an examiner that there is sufficient quality and quantity of detail in agreement to conclude that two friction ridge impressions originated from the same source. Synonymous with identification.

Innermost Recurving Ridges

A recurving ridge path that does not enclose any other recurving ridges.

Intervening Ridges

The number of friction ridges between two characteristics.

IAFIS

Integrated Automated Fingerprint Identification System. A national fingerprint and criminal history system operated by the FBI. It is being replaced by NGI.

L

Latent Print (Latent)

An impression, often not visible to the naked eye, left on crime scene evidence; generic term used for unintentionally deposited friction ridge detail. Also known as "mark" or "trace"(generally outside of North America).

Lateral Center

The left-to-right center of a fingerprint.

Left Slant Loop

A loop in which the pattern flows to the left in the impression. Also known as a left loop. A left slant loop from a right finger is a radial loop; a left slant loop from a left finger is an ulnar loop.

Level 1 Detail

The general ridge flow and pattern type in an impression. The details are not sufficient for individualization but can be used for exclusion. They may include information enabling orientation, core and delta location and distinction of finger versus palm.

Level 2 Detail

Individual friction ridge paths and associated events, including minutiae.

Level 3 Detail

Attributes related to dimensions and shapes of individual friction ridges, such as width, edge shapes, and pores.

Linear Discontinuity

Minor crease, crack, cut, thin or non-permanent scar. They are often called "white lines."

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L (continued)

Loop

A fingerprint pattern in which one or more friction ridges enter upon one side, recurve, touch or pass an imaginary line between delta and core and flow out on the same side the friction ridges entered. If the hand (left or right) is known, the types of loops are ulnar and radial loops; if the hand is unknown, the types are left and right loops.

Local Quality Issues

One or more areas within an impression containing quality or transfer issues that indicate that the anatomical friction ridge features may not have been accurately represented in the image.

M

Medial Segment

The middle segment of a finger. The thumb does not have a medial segment.

Minutia

(pl. minutiae) Events along a ridge path, including bifurcations and ending ridges; in some uses, dots are considered minutiae.

Minutiae Ridge Counts

Count of intervening ridges between specified minutiae.

N

NGI

FBI’s Next Generation Identification system which replaces IAFIS (the latent identification capability is expected to be operational in April 2013).

NCIC Classification

A pattern classification system based on the Henry system with extensions and modifications developed by the FBI and documented in the Science of Fingerprints and the Fingerprint Training Manual.

O

Orientation

The distal direction, towards the tips of the fingers.

P

Pattern Classification

Indicates the general shape or pattern of fingerprint impression (see Henry classification).

Plain Arch

A fingerprint pattern in which the ridges enter on one side of the impression and flow out the other with a rise or wave in the center. A plain arch does not have a defined up-thrust in the ridge flow at or near the point of highest curvature.

Plantar

Having to do with the friction ridge skin on the feet (soles and toes).

Pores

Small openings on friction ridges through which perspiration is released.

PPI

Pixels Per Inch: The spatial resolution of a digital image. Often referred to incorrectly as DPI (dots per inch).

Print

See impression.

Profile (EFS Profile)

Sets of EFS features to be used in latent friction ridge (fingerprint, palmprint, or plantar) searches of AFIS systems from different vendors. Different EFS Profiles are defined to allow for tradeoffs between examiner time and search accuracy.

Protrusion

An abrupt increase in ridge width that is not long enough to be called a bifurcation. Also known as a spur.

Proximal Segment

The segment of the finger or thumb closest to the palm.

R

Radial Loop

A loop in which the pattern flows in the direction of the radius bone of the forearm (toward the thumb).

Radius of Uncertainty

A circle with a selected radius of uncertainty is marked to include the area of possible locations if the precise location for a ridge ending cannot be ascertained.

Recurving Ridge

A ridge path that turns back on itself i.e. turns around in the same direction that it came from.

Region of Interest (ROI)

A single continuous friction ridge impression that includes all of the impression being evaluated while excluding as much as possible of the background and other impressions. Also used to refer to a polygon used to outline a region of interest.

Ridge

See friction ridge.

Ridge Edge Features

Protrusions and indentations at the edges of ridges.

Ridge Ending

The termination point of a single, continuous ridge.

Ridge Flow

The arrangement and direction of adjacent friction ridges.

Ridge Flow Map

A representation of the direction of ridge flow at sampling points in a grid superimposed over a friction ridge image.

Ridge Path

The course of a single friction ridge, including the starting position of the ridge, the path the ridge takes, the length of the ridge path, and where the ridge path stops.

Ridge Quality

A determination by an examiner of whether the features in the area being examined are definitive or debatable.

Ridge Quality Map (Clarity Map)

An assessment of the clarity in areas within an image. The means by which the recipient can determine whether all other features in a given area of a friction ridge impression are definitive or debatable. The quality/confidence is painted over the image (within the region of interest) using the standard colors of black, red, yellow, green, blue, and aqua; each color corresponding to a level of confidence.

Ridge Segment

A section of a ridge that connects two minutiae, so each ridge segment starts and stops either where the ridge intersects another ridge path segment (a bifurcation), ends (a ridge ending), or leaves the region of interest. (Also known as Ridge path segment).

Right Slant Loop

A loop in which the pattern flows to the right in the impression. Also known as a right loop. A right slant loop from a right finger is an ulnar loop; a right slant loop from a left finger is a radial loop.

S

Scar

A damaged area of the original structure of the skin that results in the unnatural disturbance of the ridge flow.

Skeleton

A thinned representation of the ridge structure of a friction skin image in which all pixels are white except for a thinned black skeleton following the midpoint of each ridge (also known as a ridge tracing or skeletonized image).

Spur

See protrusion.

T

Tented Arch

A type of arch fingerprint pattern that possesses either an angle, an upthrust, or two of the three basic characteristics of a loop (i.e. recurve, delta, and ridges between the core and the delta).

Type Lines

The two innermost ridges that start or go parallel, diverge and surround or tend to surround the pattern area. The pattern area includes the core(s) and delta(s).

U

Ulnar Loop

A loop in which the pattern flows in the direction of the ulna bone of the forearm (toward the little finger).

Universal Latent Workstation (ULW)

Software distributed by the FBI that provides functionality to create, edit, and view latent fingerprint transactions. ULW provides operational access to FBI IAFIS/NGI latent print services, as well as enabling cross-jurisdictional interoperability between vendor-specific AFIS feature formats.

W

Whorl

A pattern classification with two or more deltas (see exception for accidental whorls). The subclasses of whorls are accidental, central pocket loop, double loop, and plain whorls.

Whorl - Accidental

A whorl consisting of two different types of patterns, with the exception of the plain arch, with two or more deltas; or a pattern which possesses some of the requirements for two or more different types; or a pattern which conforms to none of the definitions. Some Accidental Whorls may not have two deltas that are fully defined.

Whorl - Central Pocket Loop

A whorl which has two deltas and at least one ridge which makes, or tends to make, one complete circuit, which may be spiral, oval, circular, or any variant of a circle. An imaginary line drawn between the two deltas must not touch or cross any recurving ridges within the inner pattern area.

Whorl - Double Loop

A whorl that consists of two separate loop formations with two separate and distinct sets of shoulders and two deltas.

Whorl - Plain

A whorl which consists of one or more ridges which make, or tend to make, a complete circuit, with two deltas, between which, when an imaginary line is drawn, at least one recurving ridge within the inner pattern area is cut or touched.